1. Field of the Invention
The present invention relates generally to adhesives and, more particularly, to an adhesive system and a method of making the adhesive system.
2. Description of the Related Art
It is known to use adhesives for joining parts, for sealing purposes, and for other purposes. Some adhesives, such as epoxy adhesives, typically include a separate resin and a separate hardener that remain fluid until the resin and hardener are mixed together and chemically reacted together. The resin and hardener are mixed in predetermined proportions and, after a relatively short period of time, the resin hardens or cures. Preferably, the mixture is applied where needed before curing occurs.
However, preparing and using an epoxy adhesive can be challenging. For instance, there may be too much resin in proportion to the hardener or vice versa to properly cure the epoxy adhesive. Also, the epoxy adhesive may cure before the user is able to properly apply the adhesive. Further, preparing an epoxy adhesive can be messy and inconvenient. For instance, if the components are mixed in a container with a mixing tool, both the container and mixing tool should be cleaned before the epoxy adhesive cures or else the cured epoxy adhesive will be extremely difficult to remove. Also, too much epoxy adhesive might be prepared, and the excess epoxy adhesive will be wasted.
In partial response to these disadvantages, epoxy adhesive systems were developed in which uncured resin and hardener were encapsulated within a package. Two examples of these epoxy adhesive systems are disclosed in U.S. Pat. Nos. 4,686,272 and 4,764,579. In these systems, small, discrete deposits of uncured resin are interspersed within a hardener, and the deposits are separated from the hardener by a thin, flexible, collapsible barrier film. To use the epoxy adhesive, a user presses and “kneads” the package to collapse the barrier film, thereby allowing the resin to mix with the hardener and cure. However, the barrier film may be fragile and may inadvertently collapse when the package is handled or when the package is exposed to elevated temperatures.
Therefore, it is desirable to provide an improved package of adhesive components that can be mixed and chemically reacted together to form an adhesive within the package. It is also desirable to provide an improved package of adhesive components that are less likely to inadvertently combine and cure. Thus, there is a need in the art to provide an adhesive system that meets these desires.